SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2889c955228caee48e9368c2713dc1890494cbd1cf1f264763908f444db96a81' 
  AND token = 'tj5JxGU1Vzk0oDw1H3/SMLaL4Wy1BJMRTR8w8NLvKNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}